Watching a cow chew its cud reveals only a glimpse of this animal’s bioprocessing power. At the University of California, Santa Barbara, chemical engineer Michelle O’Malley, PhD, looks at cows and other large herbivores and sees natural bioreactors.
“We initially became interested in herbivores for their powerful biomass-degrading microbes,” O’Malley says. “We used sequencing approaches combined with enrichment and lab cultivation to discover an array of biomass-degrading enzymes secreted from anaerobic fungi and bacteria.”
That work led to some unexpected results. “We were surprised in our sequencing studies of fungi from herbivores to discover that they encode building blocks for putative antibiotics and other bioactive compounds,” O’Malley explains. “Based on the fact that these genes are unique in sequence from other characterized microbes, it is likely that the fungi we characterized are making novel natural products that could find use as new drugs. In a way, it makes sense that the fungi do this because they are vastly overwhelmed in their native habitat and must have a way to distance other microbial competitors.”
Although these processes work well in the field, turning this information into better bioprocessing will take additional effort. “One challenge—beyond identifying the new products biochemically—will be scaleup,” O’Malley points out. “Natural products sourced from microorganisms are notoriously difficult to produce in so-called model systems like E. coli and yeast, and we expect that these drugs we discovered will be no different.” That obstacle, though, won’t stop O’Malley. As she concludes, “We look forward to developing the anaerobic fungi as bioprocessing platforms, which could overcome this challenge.”